CAJ | 학술논문

为探索中国野桑蚕 Bombyx mandarina 的遗传多样性及其与家蚕B.mori的系统发育关系,采用PCR产物直接测序法(少数样本克隆测序)获得34个家蚕和野桑蚕样本淀粉酶基因amy序列片段(715 bp).分析发现56个多态性位点,鉴定出28种单倍型(haplotype);核苷酸多样性π=0.01390±0.00103,单倍犁多样度Hd=0.988±0.011.核苷酸不配对分析(mismatch analysis)和Fu's Fs 检测表明中国野桑蚕曾发生过种群扩张.分子方差分析(AMOVA)表明,遗野桑蚕传差异主要在种群内,种群间和地理组群间差异不显著.聚类树上34个样本聚为3枝/3蔟,野蚕和家蚕都不按地理区域或系统(类型)聚类,A枝由来自不同地区的野蚕和不同类型的家蚕混合构成,并且进一步分成3个亚枝,每一亚枝也同时包含家蚕和野蚕,B枝南3个家蚕和1个野蚕混合构成,C枝全部由来自不同地区的野蚕构成.网络分析没有发现"祖先单倍型"和优势单倍型.结果提示,淀粉酶基因是一个多态性丰富的分子标记,中国野桑蚕遗传多样性十分丰富,据此推测家蚕起源于多种生态类型混杂的野桑蚕.
위탐색중국야상잠 Bombyx mandarina 적유전다양성급기여가잠B.mori적계통발육관계,채용PCR산물직접측서법(소수양본극륭측서)획득34개가잠화야상잠양본정분매기인amy서렬편단(715 bp).분석발현56개다태성위점,감정출28충단배형(haplotype);핵감산다양성π=0.01390±0.00103,단배리다양도Hd=0.988±0.011.핵감산불배대분석(mismatch analysis)화Fu's Fs 검측표명중국야상잠증발생과충군확장.분자방차분석(AMOVA)표명,유야상잠전차이주요재충군내,충군간화지리조군간차이불현저.취류수상34개양본취위3지/3족,야잠화가잠도불안지리구역혹계통(류형)취류,A지유래자불동지구적야잠화불동류형적가잠혼합구성,병차진일보분성3개아지,매일아지야동시포함가잠화야잠,B지남3개가잠화1개야잠혼합구성,C지전부유래자불동지구적야잠구성.망락분석몰유발현"조선단배형"화우세단배형.결과제시,정분매기인시일개다태성봉부적분자표기,중국야상잠유전다양성십분봉부,거차추측가잠기원우다충생태류형혼잡적야상잠.
Polymerase chain reaction and PCR products directly sequencing method (a few samples sequenced by cloning) were used to analyze the genetic diversity of the wild mulberry silkworm, Bombyx mandarina in China and the phylogeny of the domesticated silkworm, B. mori. A total of 715 bp nucleotides of partial amylase gene amy were sequenced in thirty-four samples from three groups of B. mandarina and four types of B. mori. Fifty-six polymorphic sites, including 28 singleton variable sites and 28 parsimony informative sites, defined 28 haplotypes. The nucleotides diversity (π) was 0. 01390 ±0.00103 and the haplotype diversity (Hd) was 0. 988 ±0.011. Mismatch analysis and Fu' s Fs test revealed the population expansion of B. mori in the past. Analysis of molecular variance (AMOVA) suggested that genetic variance mostly existed within populations and accounted for 82. 63% of total variation. Variance between population and population-groups was not significant. The phylogenetic analysis indicated that three clusters were formed by the thirty-four samples analyzed. Cluster A consisted of B. mandarina from different regions and B. mori from different types, which was further divided into three sub-clusters. Cluster B consisted of three B. mori and one B. mandarina, while cluster C consisted of B. mandarina from different regions only. There is no ancestor haplotype and dominant haplotype in the median-joining network. The results suggest that: (1) the amy gene is a molecular marker with rich diversity in silkworms; (2) there is great genetic diversity within B. mandarina population in China; and (3) the domesticated silkworm may be domesticated from multi-typed B. mandarina, which supports the theory of multiple origins from a variety of B. mandarina.